Conventionally, there has been commonly performed a method in which, when a fault is found in any of all the data stored in advance in a nonvolatile storage memory of an integrated apparatus, for example, an OS or an application (hereinafter referred to as “firmware”) after the integrated apparatus is released, the fault is cleared by rewriting the firmware with firmware for which the fault has been cleared.
For example, Patent Document 1 discloses a system adopting a dual configuration in which two versions of new firmware and current firmware are held. Here, the new firmware and the current firmware can be manually switched by an external console. According to Patent Document 1, even if there is any trouble during update, for example, power is cut off during update or an unexpected operation is performed, and update is terminated before completion, it is possible to complete update by re-performing update from the beginning from the external console. It is also possible to, if the state of update is managed, resume update not from the beginning but from the point at which the trouble occurs. Furthermore, it is possible to activate the system by switching the new firmware to the previous-version firmware. That is, there is an advantage that it is possible to resume update or return to the previous-version firmware even if a trouble occurs during update.                Patent Document 1: JP Patent Publication (Kokai) No. 11-110218A        